TIL: the biometric picture stored in the chip of my Dutch passport is a 449x599 pixels JPEG2000 file. And you can extract it with your NFC enabled mobile phone (in my case an iPhone 13 using the ReadID me app)
Cuz I do use 4kbit keys but plan to upgrade to 8kbit sooner than later...
Sadly support for 16kbit and above is at best untested if not completely unavailable.
I currently run a test trying to generate a 256kBit key but that takes already half a week so I'm not shure if the tool I'm using (#enc) can even handle that keysize...